The automatic bending of bodies, which are generally in the form of elongated rods or blades, has been achieved through an operation in which the body, which is usually fastened at an end portion of its longitudinal extension, has its free end portion submitted to only one bending through an angular displacement in the direction of the desired plastic deformation to be achieved, said displacement being carried out in a single plastic deformation operation, by applying a force to the free portion of the body that is going to be bent. Said displacement is calculated so as to guarantee a certain degree of plastic deformation to said body, based on the nominal values of molecular and physical compositions and dimension of the bodies to be bent, considering the values taken from the bending of a plurality of bodies having the same constructive and operative characteristics.
In some applications, the prior art automatic bending systems, which impart to the free portion of the body a single angular displacement in a certain direction, are sufficient to cause in the body a deformation within the precision standards required for a desired application of the body to be bent.
Nevertheless, in cases where it is fundamental to achieve a bending or plastic deformation within very restricted precision limits, these prior art automatic bending processes do not consider as relevant parameters, during the plastic deformation of each body of a plurality of equal bodies, the deviations that normally occur in terms of dimension, microstructure and molecular composition in said bodies. This problem can be solved by a sequence of bending operations which are carried out in a cumulative manner in relation to each body to be bent, until the final desired precise result is obtained. However, in terms of industrial production as, for example, in the manufacture of reed valves for hermetic compressors used in small refrigeration systems, it is impossible to achieve a precise bending of each reed valve through a practically manual control of the sequential deformation steps applied to each reed valve.
In the presently known automatic bending systems, the angular displacement, which is applied to the free portion of the body to be bent, in order to achieve a final desired plastic deformation, is calculated considering only one body with nominal characteristics, for a plurality of bodies to be bent. Except in rare occasions, the reality is that the bodies from a plurality of bodies to be bent present certain dimensional and microstructural variations relative to each other. Thus, it is impossible to achieve an automatic homogeneous degree of plastic deformation for all bodies from said plurality of bodies, without deviating from the strict precision limits which were previously set up for said bodies when defined by the reed valves of the already mentioned hermetic compressors.